BBC: Ultra-HD may need more than 120 fps
May 28, 2013
By Chris Forrester
BBC technology guru Andy Quested says that Ultra-HDTV will need much higher frame rates than today’s 24/25 frames/second or 50/60 fps, depending on content. Quested, speaking to 3D Focus says that so-called ‘image smearing’ was a risk for 4K and 8K Ultra-HDTV transmissions.
“At 50/60 [fps] though, the increased temporal resolution accentuates the smearing caused by movement when the shutter is open, but make the shutter too short and the low frame rate causes multiple images during some motion (look at what looks like a multi-arm bowler in short shutter cricket). At somewhere around 100+ fps your eyes cease to see separate images even during high movement with short shutter. More testing is needed to know what works and what doesn’t,” says Quested, whose official title is Chief Technologist HD & 3D at BBC Technology.
He said that the BBC, in conjunction with the EBU and Sony, would be testing different options at the upcoming Wimbledon tennis championships. “ ITU-R BT2020 has two U-D formats at 7,680 x 4 320 [8K) and 3,840 x 2 160 (16:9, 4K) at the following frame rates 24/1.001, 24, 25, 30/1.001, 50, 60/1.001, 60 and 120 progressive frame a second. At the moment the ITU has a paper from the UK asking for work to be done demonstrate if 120fps is a viable world frame rate. There are thoughts it needs to be higher or there need to be 50Hz multiples of either 100 or 150 fps. Tests are underway and results may take a while to resolve into standards.”